尝试这个：
SELECT *
FROM (
SELECT @cnt := COUNT(*) + 1,
@lim := 10
FROM t_random
) vars
STRAIGHT_JOIN
(
SELECT r.*,
@lim := @lim - 1
FROM t_random r
WHERE (@cnt := @cnt - 1)
AND RAND(20090301) < @lim / @cnt
) i
@H_502_4@MyISAM@H_502_4@（由于COUNT(*)@H_502_4@是即时的），此方法特别有效，但即使这样，InnoDB@H_502_4@其10@H_502_4@效率也比更高ORDER BY RAND()@H_502_4@。
这里的主要思想是我们不进行排序，而是保留两个变量并计算running probability@H_502_4@要在当前步骤中选择的行的。
如果您只需要选择一条随机记录，请尝试以下操作：
SELECT aco.*
FROM (
SELECT minid + FLOOR((maxid - minid) * RAND()) AS randid
FROM (
SELECT MAX(ac_id) AS maxid, MIN(ac_id) AS minid
FROM accomodation
) q
) q2
JOIN accomodation aco
ON aco.ac_id =
COALESCE
(
(
SELECT accomodation.ac_id
FROM accomodation
WHERE ac_id > randid
AND ac_status != 'draft'
AND ac_images != 'b:0;'
AND NOT EXISTS
(
SELECT NULL
FROM accomodation_category
WHERE acat_id = ac_category
AND acat_slug = 'vendeglatohely'
)
ORDER BY
ac_id
LIMIT 1
),
(
SELECT accomodation.ac_id
FROM accomodation
WHERE ac_status != 'draft'
AND ac_images != 'b:0;'
AND NOT EXISTS
(
SELECT NULL
FROM accomodation_category
WHERE acat_id = ac_category
AND acat_slug = 'vendeglatohely'
)
ORDER BY
ac_id
LIMIT 1
)
)
@H_502_4@假设您ac_id@H_502_4@的或多或少均匀分布。
602392714
清零编程群